tanabear: 911

Tuesday, July 27, 2010

"The greatest triumphs of propaganda have been accomplished, not by doing something, but by refraining from doing. Great is truth, but still greater, from a practical point of view, is silence about truth. By simply not mentioning certain subjects, by lowering what Mr. Churchill calls an "iron curtain" between the masses and such facts or arguments as the local political bosses regard as undesirable, totalitarian propagandists have influenced opinion much more effectively than they could have done by the most eloquent denunciations, the most compelling of logical rebuttals." Foreword to Brave New World

Sunday, June 20, 2010

NIST(The National Institute of Standards and Technology) removed their original WTC7 FAQ with the release of their Final report in December 2008. I copied and saved the original. Since it is difficult to find on-line, I'll post it here to make it more accessible to interested parties.

What was WTC 7?

The original World Trade Center Building 7 (WTC 7) was a 47-story office building located immediately to the north of the main World Trade Center (WTC) complex. Completed in 1987, it was built on top of an existing Con Edison substation and located on land owned by The Port Authority of New York and New Jersey.

When did WTC 7 collapse?

On Sept. 11, 2001, WTC 7 endured fires for almost seven hours, from the time of the collapse of the north WTC tower (WTC 1) at 10:28:22 a.m. until 5:20:52 p.m., when WTC 7 collapsed.

What caused the fires in WTC 7?

Debris from the collapse of WTC 1, which was 370 feet to the south, ignited fires on at least 10 floors in the building at its south and west faces. However, only the fires on some of the lower floors—7 through 9 and 11 through 13—burned out of control. These lower-floor fires—which spread and grew because the water supply to the automatic sprinkler system for these floors had failed—were similar to building fires experienced in other tall buildings. The primary and backup water supply to the sprinkler systems for the lower floors relied on the city’s water supply, whose lines were damaged by the collapse of WTC 1 and WTC 2. These uncontrolled lower-floor fires eventually spread to the northeast part of WTC 7, where the building’s collapse began.

How did the fires cause WTC 7 to collapse?

The heat from the uncontrolled fires caused steel floor beams and girders to thermally expand, leading to a chain of events that caused a key structural column to fail. The failure of this structural column then initiated a fire-induced progressive collapse of the entire building.

According to the report’s probable collapse sequence, heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.

Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.

The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building’s east

penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.

FPRIVATE "TYPE=PICT;ALT=drawing of typical WTC 7 floor"

Diagram 1—Typical WTC 7 floor showing locations of columns (numbered). The buckling of Column 79 was the initiating event that led to the collapse of WTC 7. The buckling resulted from fire-induced damage to floors around column 79, failure of the girder between Columns 79 and 44, and cascading floor failures.

What is progressive collapse?

Progressive collapse is defined as the spread of local damage from a single initiating event, from structural element to element, eventually resulting in the collapse of an entire structure or a disproportionately large part of it. The failure of WTC 7 was an example of a fire-induced progressive collapse.

Progressive collapse did NOT occur in the WTC towers, for two reasons. First, the collapse of each tower was not triggered by a local damage or a single initiating event. Second, the structures were able to redistribute loads from the impact and fire-damaged structural components and subsystems to undamaged components and to keep the building standing until a sudden, global collapse occurred. Had a hat truss that connected the core columns to the exterior frame not been installed to support a TV antenna atop each WTC tower after the structure had been fully designed, it is likely that the core of the WTC towers would have collapsed sooner, triggering a global collapse. Such a collapse would have some features similar to that of a progressive collapse.

How did the collapse of WTC 7 differ from the collapses of WTC 1 and WTC 2?

WTC 7 was unlike the WTC towers in many respects. WTC 7 was a more typical tall building in the design of its structural system. It was not struck by an aircraft. The collapse of WTC 7 was caused by a single initiating event—the failure of a northeast building column brought on by fire-induced damage to the adjacent flooring system and connections—which stands in contrast to the WTC 1 and WTC 2 failures, which were brought on by multiple factors, including structural damage caused by the aircraft impact, extensive dislodgement of the sprayed fire-resistive materials or fireproofing in the impacted region, and a weakening of the steel structures created by the fires.

The fires in WTC 7 were quite different from the fires in the WTC towers. Since WTC 7 was not doused with thousands of gallons of jet fuel, large areas of any floor were not ignited simultaneously as they were in the WTC towers. Instead, separate fires in WTC 7 broke out on different floors, most notably on Floors 7 to 9 and 11 to 13. The WTC 7 fires were similar to building contents fires that have occurred in several tall buildings where the automatic sprinklers did not function or were not present.

Why did WTC 7 collapse, while no other known building in history has collapsed due to fires alone?

The collapse of WTC 7 is the first known instance of a tall building brought down primarily by uncontrolled fires. The fires in WTC 7 were similar to those that have occurred in several tall buildings where the automatic sprinklers did not function or were not present. These other buildings, including Philadelphia's One Meridian Plaza, a 38-story skyscraper that burned for 18 hours in 1991, did not collapse due to differences in the design of the structural system.

Factors contributing to WTC 7’s collapse included: the thermal expansion of building elements such as floor beams and girders, which occurred at temperatures hundreds of degrees below those typically considered in current practice for fire-resistance ratings; significant magnification of thermal expansion effects due to the long-span floors in the building; connections between structural elements that were designed to resist the vertical forces of gravity, not the thermally induced horizontal or lateral loads; and an overall structural system not designed to prevent fire-induced progressive collapse.

Some people have said that a failure at one column should not have produced a symmetrical fall like this one. What’s your answer to those assertions?

WTC 7’s collapse, viewed from the exterior (most videos were taken from the north), did appear to fall almost uniformly as a single unit. This occurred because the interior failures that took place did not cause the exterior framing to fail until the final stages of the building collapse. The interior floor framing and columns collapsed downward and pulled away from the exterior frame. There were clues that internal damage was taking place, prior to the downward movement of the exterior frame, such as when the east penthouse fell downward into the building and windows broke out on the north face at the ends of the building core. The symmetric appearance of the downward fall of the WTC 7 was primarily due to the greater stiffness and strength of its exterior frame relative to the interior framing.

In videos, it appears that WTC 7 is descending in free fall, something that would not occur in the structural collapse that you describe. How can you ignore basic laws of physics?

WTC 7 did not enter free fall. According to NIST analysis of WTC 7 video, the building collapsed 18 stories in 5.3 seconds. If the building exhibited free fall, this process would have taken just 3.9 seconds. The actual collapse time exceeded the free fall time by 40 percent.

Does this mean there are hundreds or thousands of unsafe tall buildings with long span supports that must be retrofitted in some way? How would you retrofit a building to prevent this problem?

While the partial or total collapse of a tall building due to fires is a rare event, NIST strongly urges building owners, operators, and designers to evaluate buildings to ensure the adequate fire performance of structural systems. Of particular concern are the effects of thermal expansion in buildings with one or more of the following characteristics: long-span floor systems, connections that cannot accommodate thermal effects, floor framing that induces asymmetric forces on girders, and composite floor systems, whose shear studs could fail due to differential thermal expansion (i.e., heat-induced expansion of material at different rates). Engineers should be able to design cost-effective fixes to address any areas of concern identified by such evaluations.

Several existing, emerging, or even anticipated capabilities could have helped prevent the collapse of WTC 7. The degree to which these capabilities improve performance remains to be evaluated. Possible options for developing cost-effective fixes include:

More robust connections and framing systems to better resist effects of thermal expansion on the structural system.

Structural systems expressly designed to prevent progressive collapse. Current model building codes do not require that buildings be designed to resist progressive collapse.

Better thermal insulation (i.e., reduced conductivity and/or increased thickness) to limit heating of structural steel and minimize both thermal expansion and weakening effects. Insulation has been used to protect steel strength, but it could be used to maintain a lower temperature in the steel framing to limit thermal expansion. Improved compartmentation in tenant areas to limit the spread of fires.Thermally resistant window assemblies to limit breakage, reduce air supply and retard fire growth.

NIST is recommending that building standards and codes be strengthened beyond their current intent to achieve life safety to prevent structural collapse even during infrequent building fires like those in WTC 7 when sprinklers do not function, do not exist, or are overwhelmed by fire.

Did investigators consider the possibility that an explosion caused or contributed to the collapse of WTC 7?

Yes, this possibility was investigated carefully. NIST concluded that blast events inside the building did not occur and found no evidence supporting the existence of a blast event.

In addition, no blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses. According to calculations by the investigation team, the smallest blast capable of failing the building’s critical column would have resulted in a sound level of 130 decibels (dB) to 140 dB at a distance of at least half a mile, if unobstructed by surrounding buildings. This sound level is consistent with a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert.

For the building to have been prepared for intentional demolition, walls and/or column enclosures and fireproofing would have to be removed and event, NIST strongly urges building owners, operators, and designers to evaluate buildings to ensure the adequate fire performance of structural systems. Of particular concern are the effects of thermal expansion in buildings with one or more of the following characteristics: long-span floor systems, connections that cannot accommodate thermal effects, floor framing that induces asymmetric forces on girders, and composite floor systems, whose shear studs could fail due to differential thermal expansion (i.e., heat-induced expansion of material at different rates). Engineers should be able to design cost-effective fixes to address any areas of concern identified by such evaluations.

Several existing, emerging, or even anticipated capabilities could have helped prevent the collapse of WTC 7. The degree to which these capabilities improve performance remains to be evaluated. Possible options for developing cost-effective fixes include:

More robust connections and framing systems to better resist effects of thermal expansion on the structural system.

Structural systems expressly designed to prevent progressive collapse. Current model building codes do not require that buildings be designed to resist progressive collapse.

Better thermal insulation (i.e., reduced conductivity and/or increased thickness) to limit heating of structural steel and minimize both thermal expansion and weakening effects. Insulation has been used to protect steel strength, but it could be used to maintain a lower temperature in the steel framing to limit thermal expansion. Improved compartmentation in tenant areas to limit the spread of fires. Thermally resistant window assemblies to limit breakage, reduce air supply and retard fire growth. NIST is recommending that building standards and codes be strengthened beyond their current intent to achieve life safety to prevent structural collapse even during infrequent building fires like those in WTC 7 when sprinklers do not function, do not exist, or are overwhelmed by fire.

Did investigators consider the possibility that an explosion caused or contributed to the collapse of WTC 7?

Yes, this possibility was investigated carefully. NIST concluded that blast events inside the building did not occur and found no evidence supporting the existence of a blast event.

In addition, no blast sounds were heard on the audio tracks of video recordings during the collapse of WTC 7 or reported by witnesses. According to calculations by the investigation team, the smallest blast capable of failing the building’s critical column would have resulted in a sound level of 130 decibels (dB) to 140 dB at a distance of at least half a mile, if unobstructed by surrounding buildings. This sound level is consistent with a gunshot blast, standing next to a jet plane engine, and more than 10 times louder than being in front of the speakers at a rock concert.

For the building to have been prepared for intentional demolition, walls and/or column enclosures and fireproofing would have to be removed and replaced without being detected. Preparing a column includes steps such as cutting sections with torches, which produces noxious and odorous fumes. Intentional demolition usually requires applying explosive charges to most, if not all, interior columns, not just one or a limited set of columns in a building.

Is it possible that thermite or thermate contributed to the collapse of WTC 7?

NIST has looked at the application and use of thermite and has determined that its use to sever columns in WTC 7 on 9/11/01 was unlikely.

Thermite is a combination of aluminum powder and a metal oxide that releases a tremendous amount of heat when ignited. It is typically used to weld railroad rails together by melting a small quantity of steel and pouring the melted steel into a form between the two rails.

To apply thermite to a large steel column, approximately 0.13 lb of thermite would be needed to heat and melt each pound of steel. For a steel column that weighs approximately 1,000 lbs. per foot, at least 100 lbs. of thermite would need to be placed around the column, ignited, and remain in contact with the vertical steel surface as the thermite reaction took place. This is for one column … presumably, more than one column would have been prepared with thermite, if this approach were to be used.

It is unlikely that 100 lbs. of thermite, or more, could have been carried into WTC 7 and placed around columns without being detected, either prior to Sept. 11 or during that day.

Given the fires that were observed that day, and the demonstrated structural response to the fires, NIST does not believe that thermite was used to fail any columns in WTC 7.

Analysis of the WTC steel for the elements in thermite/thermate would not necessarily have been conclusive. The metal compounds also would have been present in the construction materials making up the WTC buildings, and sulfur is present in the gypsum wallboard used for interior partitions.

An emergency responder caught in the building between the 6th and 8th floors says he heard two loud booms. Isn’t that evidence that there was an explosion?

The sound levels reported by all witnesses do not match the sound level of an explosion that would have been required to cause the collapse of the building. If the two loud booms were due to explosions that were responsible for the collapse of WTC 7, the emergency responder—located somewhere between the 6th and 8th floors in WTC 7—would not have been able to survive the near immediate collapse and provide this witness account.

Did fuel oil systems in WTC 7 contribute to its collapse?

No. The building had three separate emergency power systems, all of which ran on diesel fuel. The worst-case scenarios associated with fires being fed by ruptured fuel lines—or from fuel stored in day tanks on the lower floors—could not have been sustained long enough, could not have generated sufficient heat to weaken critical interior columns, and/or would have produced large amounts of visible smoke from the lower floors which were not observed.

As background information, the three systems contained two 12,000 gallon fuel tanks, and two 6,000 gallon tanks beneath the building’s loading docks, and a single 6,000 gallon tank on the 1st floor. In addition one system used a 275 gallon tank on the 5th floor, a 275 gallon tank on the 8th floor, and a 50 gallon tank on the 9th floor. Another system used a 275 gallon day tank on the 7th floor.

Several months after the WTC 7 collapse, a contractor recovered an estimated 23,000 gallons of fuel from these tanks. NIST estimated that the unaccounted fuel totaled 1,000 ±1,000 gallons of fuel (in other words, somewhere between 0 and 2,000 gallons, with 1,000 gallons the most likely figure). The fate of the fuel in the day tanks was unknown, so NIST assumed the worst-case scenario, namely that they were full on Sept. 11, 2001. The fate of the fuel of two 6,000 gallon tanks was also unknown. Therefore, NIST also assumed the worst-case scenario for these tanks, namely that all of the fuel would have been available to feed fires either at ground level or on the 5th floor.

Why did the investigation take so long to complete?

The overall NIST investigation began on Aug. 21, 2002. Early in the investigation, a decision was made to complete studies of the two tower collapses (WTC 1 and WTC 2) before fully proceeding on the WTC 7 investigation. A major technical conference on the draft reports on WTC 1 and WTC 2 occurred on Sept. 13-15, 2005. The time between the technical conference on the WTC towers report and the issuance of this draft WTC 7 report is approximately three years, comparable to the length of a typical investigation of an aircraft crash.

The WTC 7 investigation was an extensive, state-of-the-art reconstruction of the events that affected WTC 7 and eventually led to its collapse. Numerous facts and data were obtained, then combined with validated computer modeling that is believed to be close to what actually occurred. A single computer simulation of the structural response to fires took about eight months to complete on powerful computing workstations and clusters.

Did debris from the collapse of WTC 1 cause damage to WTC 7’s structure in a way that contributed to the building’s collapse?

The debris caused structural damage to the southwest region of the building—severing seven exterior columns—but this structural damage did not initiate the collapse. The fires initiated by the debris, rather than the structural damage that resulted from the impacts, initiated the building’s collapse after the fires grew and spread to the northeast region after several hours. The debris impact caused no damage to the spray-applied fire resistive material that was applied to the steel columns, girders, and beams except in the immediate vicinity of the severed columns. The debris impact damage did play a secondary role in the last stages of the collapse sequence, where the exterior façade buckled at the lower floors where the impact damage was located. A separate analysis showed that even without the structural damage due to debris impact, WTC 7 would have collapsed in fires similar to those that occurred on Sept. 11, 2001. None of the large pieces of debris from WTC 2 (the south tower) hit WTC 7 because of the large distance between the two buildings.

Would WTC 7 have collapsed even if there had been no structural damage induced by the collapse of the WTC towers?

Yes. Even without the structural damage, WTC 7 would have collapsed from the fires that the debris initiated. The growth and spread of the lower-floor fires due to the loss of water supply to the sprinklers from the city mains was enough to initiate the collapse of the entire building due to buckling of a critical column in the northeast region of the building.

Why did WTC 7’s sprinkler systems fail during the fires?

The sprinkler systems did not fail. The collapse of WTC 1 and WTC 2 damaged the city water main. The water main served as both the primary and backup source of water for the sprinkler system in the lower 20 floors. Therefore, the sprinkler system could not function. In contrast, the sprinklers and standpipes on the building’s middle levels (21st floor through 39th floor) and upper levels (40th floor through 47th floor) received water from two large overhead storage tanks on the 46th floor, and used the city’s water mains as a backup.

How hot did WTC 7’s steel columns and floor beams get?

Due to the effectiveness of the spray-applied fire-resistive material (SFRM) or fireproofing, the highest steel column temperatures in WTC 7 only reached an estimated 300 degrees C (570 degrees F), and only on the east side of the building did the steel floor beams exceed 600 degrees C (1,100 degrees F). However, fire-induced buckling of floor beams and damage to connections—that caused buckling of a critical column initiating collapse—occurred at temperatures below approximately 400 degrees C where thermal expansion dominates. Above 600 degrees C (1,100 degrees F), there is significant loss of steel strength and stiffness. In the WTC 7 collapse, the loss of steel strength or stiffness was not as important as the thermal expansion of steel structures caused by heat.

Did the electrical substation next to WTC 7 play a role in the fires or collapse?

No. There is no evidence that the electric substation contributed to the fires in WTC 7. The electrical substation continued working until 4:33 p.m. on Sept. 11, 2001. Alarms at the substation were monitored, and there were no signals except for one event early in the day. No smoke was observed emanating from the substation.

Special elements of the building’s construction—namely trusses, girders, and cantilever overhangs, which were used to transfer loads from the building superstructure to the columns of the electric substation (over which WTC 7 was constructed) and foundation below—also did not play a significant role in the collapse.

Why were there no fatalities from the collapse of WTC 7?

Several factors contributed to the outcome of no loss of life—or serious injuries—in WTC 7. The building had only half the number of occupants on a typical day—with approximately 4,000 occupants—at the times the airplanes struck the towers. Occupants had recently participated in fire drills. The occupants, alerted by the attacks on WTC 1, WTC 2, and the Pentagon, began evacuating promptly. Evacuation of the building took just over an hour, and the process was complete before the collapse of the first WTC tower (WTC 2). Emergency responders provided evacuation assistance to occupants. No emergency responders were harmed in the collapse of WTC 7 because the decision to abandon all efforts to save WTC 7 was made nearly three hours before the building fell.

Why didn't the investigators look at actual steel samples from WTC 7?

Steel samples were removed from the site before the NIST investigation began. In the immediate aftermath of Sept. 11, debris was removed rapidly from the site to aid in recovery efforts and facilitate emergency responders’ efforts to work around the site. Once it was removed from the scene, the steel from WTC 7 could not be clearly identified. Unlike the pieces of steel from WTC 1 and WTC 2, which were painted red and contained distinguishing markings, WTC 7 steel did not contain such identifying characteristics.

Your entire investigation included no physical evidence. How can you be so sure you know what happened?

In general, much less evidence existed for WTC 7 than for the two WTC towers. The steel for WTC 1 and WTC 2 contained distinguishing characteristics that enabled it to be identified once removed from the site during recovery efforts. However, the same was not true for the WTC 7 steel. Certainly, there is a lot less visual and audio evidence of the WTC 7 collapse compared to the collapses of the WTC 1 and WTC 2 towers, which were much more widely photographed.

Nonetheless, the NIST investigation of WTC 7 is based on a huge amount of data. These data come from extensive research, interviews, and studies of the building, including audio and video recordings of the collapse. Rigorous, state-of-the-art computer methods were designed to study and model the building’s collapse. These validated computer models produced a collapse sequence that was confirmed by observations of what actually occurred. In addition to using its in-house expertise, NIST relied upon private sector technical experts; accumulated copious documents, photographs and videos of this disaster; conducted first-person interviews of building occupants and emergency responders; analyzed the evacuation and emergency response operations in and around WTC 7; performed computer simulations of the behavior of WTC 7 on Sept. 11, 2001, and combined the knowledge gained into a probable collapse sequence.

Did WTC 7 conform to building and fire codes?

The team found that the design of WTC 7 in the 1980s was generally consistent with the New York City building code in effect at that time.

WTC 7's designers intended its stairwells to evacuate nearly 14,000 occupants, anticipated at the time to be the maximum occupancy of the building. Though the stairwell’s capacity was overestimated, it was adequate for evacuating the building’s actual maximum occupancy of 8,000, and more than adequate to evacuate the approximately 4,000 occupants who were in the building on Sept. 11.

What improvements to building safety have been recommended as a result of the WTC 7 investigation?

NIST has made one new recommendation and reiterated 12 recommendations from the investigation of the WTC towers.

The new recommendation involves explicitly evaluating buildings to ensure the adequate fire safety performance of the structural system. Of particular concern are the effects of thermal expansion in buildings with one or more of the following characteristics:

long-span floor systems connections not designed for thermal effects

floor framing that induces asymmetric forces on girders, and composite floor systems whose shear studs could fail due to differential thermal expansion (i.e., heat-induced expansion of material at different rates in different directions).

Typical floor span lengths in tall office buildings are in the range of 40 ft. to 50 ft. This range is considered to represent long span floor systems. Thermal effects (e.g., thermal expansion) that may be significant in long-span buildings may also be present in buildings with shorter span lengths depending on the design of the structural system.

This investigation is the first to show how fire can cause progressive collapse in a building. It is also the first to show that under certain conditions thermal expansion effects—rather than loss of strength and stiffness due to fire—can lead to structural collapse. It is the first to analyze a building’s response behavior and determine its collapse sequence by integrating detailed models/simulations of debris impact damage, fire growth and spread, thermal analysis, collapse initiation, and collapse propagation—up to global collapse. This was an analysis of unprecedented complexity—an end-to-end computer run for the WTC towers on some powerful computers took about two months while a similar run for WTC 7 took about eight months, or about four times as long. NIST expects that the tools developed from this investigation, as well as the knowledge obtained from it, will aid in the development of more robust building design practice and in studies of future building collapse processes. These expanded tools and derived, validated, and simplified analysis approaches can guide practitioners and prevent future disasters.

Why is NIST studying the collapse of WTC 7?

The NIST investigation of WTC 7 was conducted under the National Construction Safety Team (NCST) Act, as part of its overall building and fire safety investigation of the World Trade Center disaster. The act gives NIST the responsibility for conducting fact-finding investigations of building failures that resulted in substantial loss of life or that posed significant potential of substantial loss of life. NIST has no regulatory authority under the NCST Act.

How can I provide comments on the report?

NIST welcomes comments on the draft report and recommendations—available online at http://wtc.nist.gov. Comments must be received by noon Eastern Daylight Time on Sept.15, 2008. Comments may be submitted via:

Instructions for submitting comments are available at http://wtc.nist.gov.

Have the recommendations from NIST’s investigation of the WTC towers led to any changes in building codes, standards, and practices?

The first comprehensive set of eight model building code changes based on recommendations from NIST’s investigation of the WTC towers were adopted by the International Building Code in 2007.

A second set of eight model building code changes based on NIST’s recommendations from its investigation of the WTC towers were approved by technical committees and are awaiting approval, along with potential appeals on several other code changes, at the Final Action Hearing for the 2009 edition of the International Building Code. NIST’s recommendations from its investigation of the WTC towers also have spurred actions to develop new provisions/guidelines within other standards, codes, and industry organizations, such as: the National Fire Protection Association, the American Society of Mechanical Engineers, ASTM International, the American Society of Civil Engineers, and the Council on Tall Buildings and Urban Habitat.

What specific code changes based on recommendations from NIST’s investigation of the WTC towers have been approved for inclusion in the International Building Code?

The eight specific code changes adopted in the International Building Code based on recommendations from NIST’s investigation of the WTC towers include:

1. An additional exit stairway for buildings more than 420 feet in height.

2. A minimum of one fire service access elevator for buildings more than 120 feet in height.

3. Increased bond strength for fireproofing (nearly three times greater than currently required for buildings 75-420 feet in height and seven times greater for buildings more than 420 feet in height).

4. Field installation requirements for fireproofing to ensure that:

installation complies with the manufacturer’s instructions;

the substrates (surfaces being fireproofed) are clean and free of any condition that prevents adhesion;

testing is conducted to demonstrate that required adhesion is maintained for primed, painted or encapsulated steel surfaces; and

the finished condition of the installed fireproofing, upon complete drying or curing, does not exhibit cracks, voids, spalls, delamination

any exposure of the substrate.

5. Special field inspections of fireproofing to ensure that its as-installed thickness, density and bond strength meet specified requirements, and that a bonding agent is applied when the bond strength is less than required due to the effect of a primed, painted or encapsulated steel surface. The inspections are to be performed after the rough installation of mechanical, electrical, plumbing, sprinkler and ceiling systems.

6. Increasing by one hour the fire-resistance rating of structural components and assemblies in buildings 420 feet and higher. (This change was approved in a prior edition of the code.)

7. Explicit adoption of the “structural frame” approach to fire resistance ratings that requires all members of the primary structural frame to have the higher fire resistance rating commonly required for columns. The primary structural frame includes the columns, other structural members including the girders, beams, trusses, and spandrels having direct connections to the columns, and bracing members designed to carry gravity loads.

8. Luminous markings delineating the exit path (including vertical exit enclosures and passageways) in buildings more than 75 feet in height to facilitate rapid egress and full building evacuation.

Wednesday, April 23, 2008

A paper written by Steven Jones and others has finally been published in a peer-reviewed journal. It has been a long time coming, but it was something that was bound to happen eventually. This publication seems to have sent some in the debunking community into an apoplectic rage. This is understandable because their strongest argument against us was the argument from authority. Once this argument is lost the best they can do is engage in ad hominem attacks.

The paper contains 14 points in which the 9/11 Truth Community, FEMA and NIST(National Institute of Standards and Technology) find agreement. This seems like a good starting point. The differences emerge when we get into a discussion over the causes of the collapse of WTC 1,2 and 7. These are the 14 point of agreement:

1) WTC 7 Collapse Issue. FEMA: “The specifics of the fires in WTC 7 and how they caused the building to collapse remain unknown at this time. Although the total diesel fuel on the premises contained massive potential energy, the best hypothesis has only a low probability of occurrence. Further research, investigation, and analyses are needed to resolve this issue”

3) Pancake Theory Not Supported. NIST: “NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers… Thus, the floors did not fail progressively to cause a pancaking phenomenon”

4) Massive Core Columns. NIST: “As stated above, the core columns were designed to support approximately 50% of the gravity loads” “The hat-truss tied the core to the perimeter walls of the towers, and thus allowed the building to withstand the effects of the aircraft impact and subsequent fires for a much longer time—enabling large numbers of building occupants to evacuate safely”

5) Essentially in Free Fall. NIST: [Question:] “How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2) — speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?” [Answer:] …As documented in Section 6.14.4 of NIST NCSTAR 1, these collapse times show that: “… the structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation. Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos”.

6) Fire Endurance Tests, No Failure. NIST: “NIST contracted with Underwriters Laboratories, Inc. to conduct tests to obtain information on the fire endurance of trusses like those in the WTC towers…. All four test specimens sustained the maximum design load for approximately 2 hours without collapsing

7) Fires of Short Duration. NIST: “The initial jet fuel fires themselves lasted at most a few minutes.” “At any given location, the duration of [air, not steel] temperatures near 1,000 °C was about 15 min to 20 min. The rest of the time, the calculated temperatures were near 500 °C or below”

8) WTC Fires Did Not Melt Steel. NIST: “In no instance did NIST report that steel in the WTC towers melted due to the fires. The melting point of steel is about 1,500 degrees Celsius (2,800 degrees Fahrenheit). Normal building fires and hydrocarbon (e.g., jet fuel) fires generate temperatures up to about 1,100 degrees Celsius (2,000 degrees Fahrenheit). NIST reported maximum upper layer air temperatures of about 1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers (for example, see NCSTAR 1, figure 6-36)”

9) Destruction of WTC Steel Evidence. NIST: “NIST possesses 236 structural steel elements from the World Trade Center (WTC) buildings. These pieces represent a small fraction of the enormous amount of steel examined at the various recovery yards where the debris was sent as the WTC site was cleared. It is estimated that roughly 0.25 percent to 0.5 percent of the 200,000 tons of steel used in the construction of the two towers was recovered.” “The lack of WTC 7 steel precludes tests on actual material from the structure…”.

10) Unusual Bright Flame and Glowing Liquid (WTC 2). NIST: “An unusual flame is visible within this fire. In the upper photograph {Fig 9-44} a very bright flame, as opposed to the typical yellow or orange surrounding flames, which is generating a plume of white smoke, stands out”.

11) High-Temperature Steel Attack, Sulfidation. FEMA (based on work by a Worchester Polytechnic Institute investigative team): “Sample 1 (From WTC 7)… Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent intergranular melting, was readily visible in the near-surface microstructure…. Sample 2 (From WTC 1 or WTC 2)… The thinning of the steel occurred by high temperature corrosion due to a combination of oxidation and sulfidation. …The severe corrosion and subsequent erosion of Samples 1 and 2 are a very unusual event. No clear explanation for the source of the sulfur has been identified… A detailed study into the mechanisms of this phenomenon is needed…"

12) Computer Modeling and Visualizations. New Civil Engineer: "World Trade Center disaster investigators [at NIST] are refusing to show computer visualisations of the collapse of the Twin Towers despite calls from leading structural and fire engineers, NCE has learned. Visualisations of collapse mechanisms are routinely used to validate the type of finite element analysis model used by the [NIST] investigators. …"

13) Total Collapse Explanation Lacking. NIST: “This letter is in response to your April 12, 2007 request for correction… we are unable to provide a full explanation of the total collapse.”

14) Search for Explosive or Thermite Residues. From a NIST FAQ: [Question: ] “Did the NIST investigation look for evidence of the WTC towers being brought down by controlled demolition? Was the steel tested for explosives or thermite residues? The combination of thermite and sulfur (called thermate) "slices through steel like a hot knife through butter." [Answer: ] NIST did not test for the residue of these compounds in the steel”.

It can be seen from the above examples that NIST has failed miserably in their attempts to explain the collapse within the confines of the official story. By only going up to the point of collapse initiation they absolve themselves of having to deal with the obvious evidence that explosive charges were used to destroy the towers. A real investigation should cover the entire collapse, not just the initiation. Will we ever get a thorough and complete investigation?

Saturday, March 1, 2008

Mark Roberts is considered by some to be the greatest defender of the the official 9/11 story and the greatest debunker of the 9/11 Truth Movement. His encyclopedic knowledge of 9/11 is so vast that no one should dare challenge his towering intellect. Anyone who steps into the ring with him is bound to get clobbered. He is the 800 pound gorilla who's mere presence causes truthers to run for the hills. In reality, he is more comparable to a scarecrow, from a distance he may look menacing, but upon closer inspection he is just made out of straw.

So where is Mark Roberts wrong? This was a question posed to members of the 9/11 Truth Movement. Mark Roberts wrote a long paper on the collapse WTC7, or more to the point, the "lies" of the 9/11 Truth Movement and their beliefs regarding WTC7. The goal of his paper was to attack people for asking questions about WTC7, not to discover how the building collapsed. In fact, Mark Roberts does not devote a single sentence to explain how WTC7 collapsed. This is not surprising since the government has yet to offer an explanation for the collapse. If someone does not have an explanation for something, then it is not possible to say where their explanation is wrong. So I will move on and show where Mark Roberts is wrong regarding the Pentagon attack.

Where did the right wing impact the Pentagon? Mark Roberts has this picture on his website.

Mark Roberts states this regarding the "hole", "The hole made by flight 77 extends along the wing line, left and right of the fuselage hole. It is not a cookie-cutter hole: that simply cannot happen when a plane hits a heavily- reinforced concrete building. Flight 77 hit the Pentagon at a 43-degree angle to its west wall. It came from the right of the photo below." If the right wing hit within the area shown by the rectangle, then this contradicts the information in the Pentagon Building Performance Report(PBPR). At the moment of impact the plane was tilted to the left between 7 to 9 degrees. The PBPR states, “The left wing passed below the second-floor slab, and the right wing crossed at a shallow angle from below the second floor slab to above the second-floor slab.” It goes on and reports, "The right wing was below the second-floor slab at the fuselage but above the second-floor slab at the tip, and the left wing struck the building entirely below the second-floor slab, to the north of column line." So the right wing could not have damaged all of the area within the rectangle. Somewhere between column line 17 and 18 the right wing should have impacted the second floor slab and gone up from there. Mark Roberts has the all impact beneath the 2nd floor slab. So for Mark Roberts to be accurate, he should show the rectangle at a slight upwards tilt. If he does, will he refer to this as the “hole” and no longer refer to the damage on the first floor as the “hole”? The area beneath the first floor slab appears to be more damaged so maybe that is why he chose to show the impact there. If the right wing is sloped upwards slightly a "hole" becomes less obvious.

This also brings up another important issue. Regardless of where the right wing impacted the building, how were the columns behind the facade, where the right wing hit the Pentagon, damaged? If the wing disintegrated or folded back what caused the damage to the columns behind column lines 15 to 18. If the wing never punctured a clear hole through the facade, how were the columns on the other side damaged?

Of course, I don’t know if Mark Roberts is wrong, because I don’t presume to know everything that happened that day. However, we can say that his claim contradicts the information in the PBPR.

Thursday, February 14, 2008

What are the best arguments against the claims made by members of the 9/11 Truth Movement? Well, if you actually try to debate with "debunkers" you will find that few actually discuss the evidence or provide proof for their assertions. They will often use straw-man arguments and avoid debate by appealing to certain philosophical principles, namely Ockham's razor. Ockham's razor, also known as the principle of economy, can been described several ways, "Entities should not to be multiplied beyond necessity... Plurality should not be posited without necessity... All other things being equal, the simplest solution is the best" etc. The appeal to Ockham's razor is frequently made by defenders of the official story. It is usually made when someone has no evidence to support their assertion.

I had a discussion with Totovader, someone who is skeptical of the claims made by the 9/11 Truth Movement. Totovader posted on his website a column entitled, "Why should the 'Truth' be divided." He stated that members of the Truth Movement do not base their explanations on evidence, therefore, different people will come to radically different conclusions regarding the events of that day. An example would be the debate over how the towers collapsed. Was it a space beam, or explosive charges? Totovader wrote, "They don’t seem to understand that each of these theories contradict each other and any act to resolve those contradictions will lead to the conclusion they must avoid: that they’re all horribly, horribly wrong." Actually, we do understand that these claims contradict each other, that is why Steven Jones left Scholars for 9/11 Truth and founded his own group. The space beam hypothesis has been thoroughly discredited(assuming it had credit) by physicist Gregory Jenkins. It should be expected that the 9/11 Truth Movement will have disagreements. We aren't claiming that we know they entire truth, we want to know the truth. When individuals are trying to understand a complex event it is natural that alternative explanations will arise. A social, political or scientific movement that has no internal disagreements is a cult. This describes people who believe the official 9/11 story.

So what about contradictory explanations made by the defenders of the official story? I provided a specific example to Totovader, the hole in the C-Ring of the Pentagon. What was the cause? People defending the official story have provided several explanations, the nose of the plane; one of the engine's; a shockwave from the impact; a ball of energy, the plane's landing gear, the plane becoming like an artillery shell or tank round. Which one is true? Totovader didn't know. He responded, "I reserve the right to change my position- and in fact often do- based on the available evidence. That’s what science is." So then I asked him what pieces of evidence caused one explanation to be accepted and another to be discarded. He had no answer. If the explanation is changing based on evidence this should be easy to do. So by what criteria are defenders of the official story changing their explanations? The explanations change based on the principle of the least absurd. There might be many explanations one could posit to explain a given phenomenon, so the goal is to come up with the least absurd that is compatible with the government's story. Once it is shown that this explanation is to implausible, the goal is to try to find another less absurd explanation.

The original explanation was that the nose cone made the hole in the C-ring. After all the hole is round and the nose of the aircraft is round so that sounds plausible. However, the nose is quite fragile and it is unlikely that it could have punched a hole completely through the C-Ring. The Pentagon Building Performance Report(PBPR) states, "These data suggest that the front of the aircraft disintegrated essentially upon impact..." After this explanation became to ridiculous to maintain others scenarios were given. The most famous one was by Popular Mechanics. They stated as fact that the hole was caused by the landing gear of the plane. However, the PBPR report does not tell us what caused this hole, they only mention its existence. They do state that the landing gear was found 300 ft. into the structure, but that the hole in the C-Ring was 310 ft. from the impact point. This explanation now seems to have been dropped as well. In the History Channel Documentary, "9/11 Conspiracies, Fact or Fiction", a new explanation is given. Allyn Kilsheimer states, "The plane became almost like an artillery shell or tank round." I wonder how long this new theory will last?

I asked Totovader if a Rapid Wall Breaching Kit(RWBK) could have created this hole. His response was predictable, "It is irrational and entirely contradictory to claim that the hole in the wall has some other cause. If nothing else, Occam’s razor should tell you that." Why should Occam's razor tell me that? If a theory can't do justice to all the available evidence then it is entirely appropriate to try to find other explanations. He goes on, "Therefore, it is not incumbent on the “government” to explain this hole-" Why not? If it is not incumbent on the government to explain this and other events of that day, then who is responsible? According to Penn Jillette, "A real skeptic demands to be convinced with evidence." Does Totovader sound like someone who is demanding to be convinced?

The other issue this topic brings up is where does the burden of proof lie? Does the burden lie with the government or with the Truth Movement? What about the claims by the Bush Administration that Iraq was producing WMD? I asked Totovader, "Did the burden lie with the Bush Administration officials to prove its claims, or for Scott Ritter to prove that Iraq did not have WMD? After all, the fact that Saddam was producing WMD was the widely accepted version of events." Naturally, he did not answer the question.

The "debunkers" survive by avoiding honest debate, not answering questions and by engaging in irrelevant philosophical meanderings.

"Galileo wrote to Kepler wishing they could have a good laugh together at the stupidity of 'the mob.'; the rest of his letter makes it plain that 'the mob' consisted of professors of philosophy, who tried to conjure away Jupiter's moons, using 'logic-chopping arguments as though they were magical incantations'" Bertrand Russell

Sunday, February 3, 2008

At the end of the column by Michael Shermer he has a link to an article written by Phil Mole for the Skeptic magazine. It was published for the fifth anniversary of the attacks. The majority of the people who attempt to write about the 9/11 Truth Movement do not know the first thing about it or the events of that day. They start off with the premise that our ideas are absurd and there is no reason to take our claims seriously. Any claims made by the 9/11 Truth Movement is instantly discarded and any claim made by a "debunker" is accepted as legitimate. There is no skepticism applied to the claims made by those defending the government. This is also the case with Phil Mole which I will demonstrate.

Phil Mole attended a Truth Conference in Chicago sponsored by 9/11truth.org. He stated that the goal of the conference was for "attendees to consolidate their group identity..." What is this suppose to mean? He appears as though he is trying to give the impression that we are some kind of cult, maybe not that much different from the one headed by Jim Jones. Wasn't "The Amazing Meeting! 5.5" a way for "skeptics" to consolidate their group identity as well? He goes on to say, "As someone who does not share the views of the 9/11 Truth Movement, I have another objective. I want to listen to their arguments and view their evidence, and understand the reasons why so many likable and otherwise intelligent people are convinced that the United States government planned the murder of nearly 3,000 of its own citizens. "

His first topic is the destruction of World Trade Towers 1 & 2. He lists the evidence made by the conspiracy theorists that WTC1,2 were destroyed by a controlled demolition. This includes the fact that the collapse looks like a demolition, the speed of the collapse, the fact that jet-fuel fires do not melt steel, and the demolition squibs(i.e. mistimed explosions). He attempts to counter each one. His argument against the collapse resembling a controlled demolition is the fact that controlled demolitions begin at the bottom, not the top. This is a weak argument. A controlled demolition means that explosives are precisely timed. They can go off in any order. This is ultimately a straw man argument, as no one in the Truth Movement is saying that WTC1,2 were blown up from the bottom, or that they resembled an implosion. He goes on to state, "but what are the chances that those planning such a complicated demolition would be able to predict the exact location the planes would impact the towers, and prepare the towers to begin falling precisely there?" The planes were probably remotely piloted into the buildings. Therefore, there could be great precision on where they would impact the towers.

He next discusses whether or not the fires could have weakened the steel to lead to a collapse of the buildings. He states, "engineering estimates tell us that steel loses 50% of its strength at 650° F, and can lose as much as 90% of its strength at temperatures of 1,800° F. Even if we assume temperatures of no higher than 1,000° F during the fire, we would still have more than enough reasons to expect damage severe enough to result in eventual collapse. " This is another bad argument. First, he is confusing the temperatures of the fire with the temperatures of the steel. Also he does not say what percentage of the steel would have to heat up to 1,000° F for structural collapse to ensue. NIST found that only 2% of the steel tested on the perimeter columns got over 250C(482F) and none of the core columns. They also found, "Microstructure tests showed no steel reached critical (half-strength) values (600 C, 1112 F)." Besides, if fire temperatures of only 1,000° F can cause an entire building to be destroyed, then why hasn't this happened before?

His next discussion is whether or not there was molten steel found in the rubble pile of the collapsed buildings. He states, "However, the sources in question are informal observations of “steel” at Ground Zero, not laboratory results." This is not entirely true. In Appendix C: Limited Metallurgical Examination of the FEMA Report, they found, “Evidence of a severe high temperature corrosion attack on the steel, including oxidation and sulfidation with subsequent INTERGRANUAL MELTING, was readily visible in the near-surface microstructure.”

What about the "squibs"? He states, "these are plumes of smoke and debris ejected from the building due to the immense pressure associated with millions of tons of falling towers." This cannot be true, as many of the "squibs" were emerging from floors that had no smoke. If it was due to increased pressure, it would be uniform across the floor. It would not emerge from localized points.

His discussion of WTC7 is weak. A lot of the discussion has to do with what did Larry Silverstein really mean when he used the phrase, "pull it." It is incumbent on the government to prove how WTC7 collapsed. This they have not done. Shyam Sunder, the head of the NIST investigation said, "We are studying the horizontal movement east to west, internal to the structure, on the fifth to seventh floors.… But truthfully, I don’t really know. We’ve had trouble getting a handle on building No. 7." Maybe a similar level of humility would be good for the "debunkers" to exhibit every now and then, instead of pretending they have all the answers.

His next topic of discussion is the Pentagon. The government has yet to show conclusively what happened there. He devotes a lot of attention to the statement made by Jamie McIntyre. As in the case of WTC7, interpreting what someone actually meant is largely a waste of time. What the physical evidence shows is far more important. Why is there no tail damage to the facade? This issue is not even brought up by Phil Mole. Yet the problem is clearly mentioned in the Pentagon Building Performance Report(PBPR). It states, "The height of the damage to the facade of the building was much less than the height of the aircraft’s tail. At approximately 45 ft, the tail height was nearly as tall as the first four floors of the building. Obvious visible damage extended only over the lowest two floors, to approximately 25 ft above grade." Then it drops the issue as it is not important to explain. What about the hole in the C-Ring? The PBPR gives no explanation for it. All of these important anomalies are not even mentioned, but they are critical if we are to understand the events of that day.

His discussion of Flight 93 does not focus on the size of the debris field, only on where the engine was found. What about a second debris field at Indian Lake, and third one near New Baltimore over eight miles away? There is no mention of this. He also fails to mention that there was little evidence of a plane crash.

Konicki: "Na, there was nothing, nothing that you could distinguish that a plane had crashed there."

Wally Miller: "The smoking crater looked, he says, 'like someone took a scrap truck, dug a 10-foot ditch and dumped all this trash into it.'"

Reporter Jon Meyer: "There was no plane to be found."

Pat Madigan: "Where was the plane crash?"

Ernie Stull, mayor of Shanksville, "There was no plane."

Regarding the issue of a NORAD stand down, he does not mention the numerous contradictions within the government's own story, nor does he explain why NORAD generals apparently lied under oath. He also does not mention the testimony made to the 9/11 Commission by Norman Mineta while he was in the PEOC.

Phil Mole concludes, "This article has analyzed the arguments of the 9/11 Truth Movement and found them lacking." Maybe he found them lacking because his research was very poor and superficial. He goes on, "any theory needs evidence in its favor if it is to be taken seriously." This is true. The evidence that the 9/11 Truth Movement has accumulated against the government's story is overwhelming. Phil Mole did not set out to learn about the evidence. His goal was to write another hit piece against the 9/11 Truth Movement.

Thursday, January 31, 2008

Michael Shermer wrote a column for the Huffingtonpost yesterday where he describes his encounters with members of the 9/11 Truth Movement while on his book tour. The name of the article is, "9/11 'Truthers' a Pack of Liars". Then at the end of the article he attempts to compare us to the Holocaust denial movement. Since he calls us a "pack of liars", it would be helpful if he would actually mention some of the lies we routinely make. This he did not do. He details his conversation with a Truther,

"There has been a disinformation campaign going on ever since 9/11.""How do you know?" I inquired."Because of all the unexplained anomalies surrounding 9/11," he answered."Such as?""Such as the fact that steel melts at a temperature of 2,777 degrees Fahrenheit, but jet fuel burns at only 1,517 degrees Fahrenheit. No melted steel, no collapsed towers."Shermer goes on to state, "At this point I ended the conversation and declined to be interviewed, knowing precisely where the dialogue was going next--if I cannot explain every single minutia about the events of that fateful... day...that lack of knowledge, in his mind at least, equates to direct proof that 9/11 was orchestrated by Bush, Cheney, Rumsfeld, and the CIA."

Maybe Shermer decided to the end conversation, because he knows very few facts regarding the events of that day. Why does Michael Shermer consider the destruction of 3 buildings, to be a "minutia" of the events that day? The government's theory is that two jetliners caused three buildings to be destroyed that day, and other buildings to be significantly damaged. This is not "minutia", this is the government's whole case. If they can't prove this, their whole theory and explanation for what happened that day falls apart. NIST(The National Institute of Standards and Technology) was tasked with investigating and explaining the collapse of WTC1,2 and 7. They released their final report on Towers 1 and 2 in October 2005. However, they only carry their analysis until the point of collapse initiation. They also stated in a response to a Request for Correction that they were, "...unable to provide a full explanation of the total collapse." They have yet to release their report on WTC7.

Michael Shermer stated at the end of his column, "No holes, no Holocaust. No melted steel, no Al-Qaeda attack. " This is a bad analogy. We aren't denying that people were killed, only how it happened. The government has yet to provide answers.